Field of the Invention
The present disclosure generally relates to information processing and, more particularly to an information processing apparatus, an information processing method, storage medium, and to a technique for measuring a three-dimensional shape of a surface of a measurement target object by projecting a projection pattern onto the measurement target object and capturing a projection image thereof.
Description of the Related Art
As a measurement algorithm of a three-dimensional sensor, there is a method of projecting a projection pattern onto a measurement target object and measuring a distance to the measurement target object and a plane direction of the measurement target object, from an image obtained by capturing an image of the projected projection pattern. Information on the measured distance and the plane direction can be used for, for example, three-dimensional shape inspection of the measurement target object, model fitting, conversion to a surface shape model (formed by polygon, etc.) and the like.
Japanese Patent Application Laid-Open No. 6-281433 discusses a technique for projecting two lines (hereinafter, a linear light ray projected onto an object is referred to as a “measurement line”) onto a measurement target object and measuring a distance to the measurement target object based on a principle of a light-section method. According to Japanese Patent Application Laid-Open No. 6-281433, a plane direction of the measurement target object is calculated by forming a triangle mesh between the two measurement lines used to measure the distance. Here, the triangle mesh formed between the measurement lines is nearly an equilateral triangle, and as the area of the triangle mesh is smaller, a local plane of the measurement target object is well approximated. Therefore, by reducing the space between the measurement lines so as to reduce the area of the triangle mesh formed therebetween, the accuracy in measuring the plane direction increases.
However, according to the method discussed in Japanese Patent Application Laid-Open No. 6-281433 described above, there are only two measurement lines to be projected, and thus there are such shortcomings that it is difficult to obtain the distances to a plurality of planes of the measurement target object and the plane directions of the plurality of planes through a single instance of imaging.